function [X_dot] = plant_o(x,U,t)

global g I l m_p Jx Jy Jz
global a1 a2 a3
global b1 b2 b3
X_dot = zeros(12,1);
x_o = x(:,5);
% 几何中心位置

tmp = zeros(1,3);

% 合力和合力矩
D = 0;
D_phi = 0.1*D; D_theta = 0.1*D; D_psi = 0.1*D;

X_dot(1) = x_o(2);
X_dot(2) = (U(4) + tmp(1))/ Jx + x_o(4)*x_o(6)*a1 + D_phi;
X_dot(3) = x_o(4);
X_dot(4) = (U(5) + tmp(2)) / Jy + x_o(2)*x_o(6)*a2 + D_theta;
X_dot(5) = x_o(6);
X_dot(6) = (U(6) + tmp(3)) / Jz + x_o(2)*x_o(4)*a3 + D_psi;

% 位置状态
X_dot(7)  = x_o(8); 
X_dot(8)  = U(1)/m_p + D;
X_dot(9)  = x_o(10); 
X_dot(10) = U(2)/m_p + D ;
X_dot(11) = x_o(12); 
X_dot(12) = -g + U(3)/m_p + D;

end 